Radio frequency device and method using digital controllable scatterer (DCS)

Abstract

The invention provides a radio frequency device, comprising: a DCS (102) wherein the DCS (102) comprises a surface (104), the surface (104) comprising scattering elements (106), the scattering elements (106) having a controllable phase shift; an emitter (108) for emitting electromagnetic waves (110) onto the scattering surface of the DCS; and a DCS controller (112). The DCS controller determines a codeword based on one or more parameters of the DCS, characteristics of the electromagnetic waves emitted by the emitter, and characteristics of desired electromagnetic waves scattered by the scattering surface of the DCS 102. The codeword determines a phase shift configuration of the plurality of scattering elements of the scattering surface of the DCS. Then, the DCS controller uses the codeword to control the scattering elements of the scattering surface of the DCS to form the desired electromagnetic waves (114) by scattering the electromagnetic waves emitted by the emitter.

Description

Technical Field

[0001] The present invention relates to radio frequency devices and systems using a digitally controllable scatterer (DCS). The present invention provides a radio frequency device for forming a desired electromagnetic wave from an impinging wave using a codeword. A corresponding method and a computer program product are also provided. Background Art

[0002] In addition to traditional applications in wireless communication systems, electromagnetic systems have also attracted extensive attention in many fields such as radar (RADAR), lidar (LiDAR), sensing, motion and object detection, imaging, and holography.

[0003] The use of radio waves has increased significantly in many fields with diverse applications, mainly due to progress in the utilization, propagation, and interaction of radio waves with the propagation environment. With the multiplication of transmit and receive antennas, it is possible to more efficiently control the propagated electromagnetic wave in the propagation environment. This benefits from channel estimation and channel state information acquisition. This technology involves estimating the propagation medium in order to correctly adjust the radiation patterns of the receive and transmit antennas according to the expected application, based on the estimated propagation medium.

[0004] Recently, adjusting the propagation medium according to the needs of the expected application has started to receive attention. This concept is called channel programming, which includes introducing passive reflection or scattering elements in the propagation environment to adjust the propagation medium, called the propagation channel.

[0005] Passive or semi-passive reflection surfaces, called Reflective Intelligent Surface (RIS), Large Intelligent Surface (LIS), or digitally controllable scatterer (DCS), are essentially very large surfaces composed of a large number (e.g., hundreds or thousands) of scattering elements with controllable phase shifts. The phase shifts of these scattering elements can be adjusted to change the perceived propagation channel between two communication nodes, where one node is the transmitter (or source) and the other node is the receiver (or target).

[0006] Drawing on communication tools, the processing and selection of the phase shifts to be applied to the different scattering elements that make up a DCS are carried out according to signal processing techniques through a channel estimation process. Several technical solutions have been proposed in this regard. However, these technical solutions are difficult to implement in practical applications because of their huge computational complexity and long convergence time. It is worth noting that, relative to the number of scattering elements that make up the surface of the DCS, their complexity grows exponentially.

[0007] Codewords can be defined based on channel state information collection, that is, the appropriate phase configuration applied to the scattering elements of the DCS, and then the DCS can be adapted to the given constraints of the received signal according to the contribution of the propagation channel and the DCS.

[0008] In addition, the representation, storage, and exchange of codewords require information with a large number of values, and the number of these values is equal to the number of scattering elements of the DCS.

[0009] Furthermore, traditional codeword generation methods cannot coordinate different wavefront processes. That is to say, the design of traditional codewords only targets the far-field incident wavefront (plane wave) to the far-field scattered wavefront (plane wave), or only targets the near-field incident wavefront (spherical wave) to the near-field scattered wavefront (spherical wave). Summary of the Invention

[0010] In summary, the present invention aims to improve the traditional technical solutions of devices using DCS. One objective is to achieve an optimal configuration (i.e., codeword) of the scattering elements of the DCS in order to perform transformation or filtering functions on the electromagnetic wavefront. In other words, the technical solution provided by the present invention aims to achieve the phase configuration of the scattering elements of the DCS according to the incident electromagnetic wave generated by the source and the desired outgoing electromagnetic wave for the intended application and target. In other words, the present invention proposes a general systematic process for generating codewords for the DCS.

[0011] This and other objectives are achieved by the present invention according to the solutions described in the independent claims. Advantageous implementations are further described in the dependent claims.

[0012] A first aspect of the present invention provides a radio frequency device. The radio frequency device includes: a DCS, wherein the DCS includes a scattering surface, the scattering surface includes a plurality of scattering elements, and each scattering element has a controllable phase shift; a transmitter for transmitting an electromagnetic wave onto the scattering surface of the DCS; a DCS controller for determining a codeword according to one or more parameters of the DCS, the characteristics of the electromagnetic wave transmitted by the transmitter, and the characteristics of the desired electromagnetic wave scattered by the scattering surface of the DCS; and using the codeword to control the scattering elements of the scattering surface of the DCS to form the desired electromagnetic wave by scattering the electromagnetic wave transmitted by the transmitter. The codeword determines the phase shift configuration of the plurality of scattering elements of the scattering surface of the DCS.

[0013] The advantage of this is that the DCS is configured and controlled to generate an electromagnetic signal that can be applied to different scenarios, applications, and configurations. In other words, the radio frequency device provided by the present invention can configure the surface of the DCS in a controlled manner to manipulate the propagating electromagnetic wave transmitted by the transmitter and scatter these electromagnetic waves as expected, for example, scatter towards an area of interest or towards a target.

[0014] More advantageously, the radio frequency device provided by the present invention can directly generate a compressed codeword using several parameters, thereby reducing the computational complexity and further reducing the codeword storage and exchange between different components in the radio frequency device. In addition, such a compressed codeword can be regarded as explicitly eliminating the characteristics of the DCS, so a higher level of abstraction (i.e., a generalized version of the codeword) is obtained, and this abstraction can be decompressed by considering the characteristics of the DCS, that is, adapted to the DCS.

[0015] In the present invention, codeword generation refers to constructing and configuring the phase shift of each of the scattering elements of the DCS.

[0016] In addition, in the present invention, the terms "wave" and "wavefront" can be used interchangeably. In addition, the terms "electromagnetic signal" and "electromagnetic wave / wavefront" can also be used interchangeably.

[0017] It should be noted that although the radio frequency device of the first aspect includes a transmitter, the transmitter is not necessarily part of the radio frequency device, that is, the radio frequency device does not necessarily include a transmitter.

[0018] In one implementation of the first aspect, the characteristics of the electromagnetic wave transmitted by the transmitter include at least one of the propagation vector and the structure of the electromagnetic wave transmitted by the transmitter.

[0019] In the present invention, the characteristics of the electromagnetic wave emitted by the transmitter considered by the DCS controller refer to the characteristics of the electromagnetic wave at the DCS, that is, the characteristics of the electromagnetic wave when it impinges on the scattering surface of the DCS (after passing through the channel between the transmitter and the DCS).

[0020] Optionally, the DCS controller may also consider the characteristics of the electromagnetic wave at the transmitter (before passing through the channel between the transmitter and the DCS). For example, the characteristics of the electromagnetic wave impinging on the scattering surface of the DCS can be determined based on the characteristics of the electromagnetic wave at the transmitter using a transfer function, where the transfer function is based on the knowledge of the channel between the transmitter and the DCS.

[0021] In one implementation of the first aspect, the characteristics of the desired electromagnetic wave scattered by the scattering surface of the DCS include at least one of the desired propagation vector and the structure of the desired electromagnetic wave scattered by the scattering surface of the DCS.

[0022] In one implementation of the first aspect, the one or more parameters of the DCS include at least one of the position of the DCS, the orientation of the DCS, the size of each scattering element of the scattering surface of the DCS, and the total number of scattering elements of the scattering surface of the DCS.

[0023] By simultaneously considering the characteristics of the electromagnetic wave emitted by the transmitter, the characteristics of the desired electromagnetic wave scattered by the DCS, and the parameters of the DCS itself, all possible scenarios (near field and / or far field) can be considered when generating the codeword.

[0024] In one implementation of the first aspect, the DCS controller is further configured to: determine the characteristics of the electromagnetic wave emitted by the transmitter, or obtain the characteristics of the electromagnetic wave emitted by the transmitter through the signaling of the transmitter. Additionally or alternatively, the DCS controller is further configured to: determine the characteristics of the desired electromagnetic wave scattered by the scattering surface of the DCS, or obtain the characteristics of the desired electromagnetic wave scattered by the scattering surface of the DCS through the signaling of the transmitter.

[0025] The advantage of doing so is that the complexity can be reduced and the information exchange between different components in the radio frequency device can be decreased.

[0026] In one implementation of the first aspect, the position of the transmitter and the position and orientation of the DCS are fixed relative to each other.

[0027] In one implementation of the first aspect, the DCS controller is further configured to: determine an optimal quadratic surface Q based on a quadratic surface Q that behaves as a perfect electric conductor (PEC), based on the characteristics of the electromagnetic wave emitted by the emitter, and based on the characteristics of the desired electromagnetic wave scattered by the scattering surface of the DCS * , where the optimal quadratic surface describes the transformation of the electromagnetic wave emitted by the emitter to form the desired electromagnetic wave scattered by the scattering surface of the DCS; determine the phase shift of each scattering element in the scattering surface of the DCS as a function of one or more parameters of the optimal quadratic surface Q * .

[0028] In the present invention, codewords can be customized based on the reflection characteristics of the quadratic surface and its parameters, which describe the required or desired transformation that the surface of the DCS is to apply to the electromagnetic wave transmitted to the DCS, and then the behavior of the quadratic reflection surface is mapped to the DCS. This mapping can include determining the phase shift of each scattering of the scattering elements on the surface of the DCS such that the wave scattered by the DCS can be the same as the wave reflected by a mirror having the shape of a quadratic surface

[0029] Thus, the codewords can be compressed using a minimum number of parameters, which is at most the number of parameters defining the determined quadratic surface. More advantageously, the generated codewords can encode the phase shift that needs to be applied individually to each scattering element in the scattering elements of the DCS to form the desired electromagnetic wave scattered by the DCS

[0030] In addition, several codewords and a codebook (a set of codewords) can be generated on the fly according to a quadratic expression

[0031] In one implementation of the first aspect, the canonical equation of the quadratic surface Q is:

[0032] where a, b, c, d, α 1 , α 2 , β 1 , β 2 , γ 1 , γ 2 and τ are parameters of the quadratic surface Q, and α 2 , β 2 , γ 2 , τ ∈ {0, 1}

[0033] In the present invention, the term "quadratic surface" refers to both a conic section in 2D and a quadratic surface in 3D

[0034] In one implementation of the first aspect, the DCS controller is further configured to determine, according to the minimum distance between the optimal quadratic surface Q * and the scattering surface of the DCS, the phase shift of each scattering element among the scattering elements of the scattering surface of the DCS.

[0035] In one implementation of the first aspect, the codeword indicates the determined phase shift of each scattering element among the scattering elements of the scattering surface of the DCS, such that by using the codeword to control the scattering elements of the scattering surface of the DCS, the electromagnetic wave emitted by the transmitter can be scattered according to the reflection of the quadratic surface.

[0036] In one implementation of the first aspect, the radio frequency device further includes: a target, where the target is irradiated by the desired electromagnetic wave scattered by the scattering surface of the DCS.

[0037] In one implementation of the first aspect, the target is a receiver, and the receiver is configured to receive the desired electromagnetic wave scattered by the scattering surface of the DCS.

[0038] In one implementation of the first aspect, the DCS controller is further configured to obtain the characteristics of the desired electromagnetic wave scattered by the scattering surface of the DCS through the signaling of the target. Alternatively, the DCS controller is further configured to obtain the characteristics of the desired electromagnetic wave scattered by the scattering surface of the DCS by using information about the target.

[0039] By simultaneously considering the target and / or the receiver, the versatility of the proposed radio frequency device can be enhanced by implementing different configurations and increasing the range of possible applications, including beam focusing, single-user and multi-user focusing, holograms, and sensing, etc.

[0040] A second aspect of the present invention provides a radio frequency device. The radio frequency device includes: a DCS, where the DCS includes the scattering surface, the scattering surface includes a plurality of scattering elements, and each scattering element has a controllable phase shift; a DCS controller. The DCS controller is configured to: determine a codeword according to one or more parameters of the DCS, the characteristics of the electromagnetic wave hitting the scattering surface of the DCS, and the characteristics of the desired electromagnetic wave scattered by the scattering surface of the DCS; use the codeword to control the scattering elements of the scattering surface of the DCS to form the desired electromagnetic wave by scattering the electromagnetic wave hitting the scattering surface of the DCS. The codeword determines the phase shift configuration of the plurality of scattering elements of the scattering surface of the DCS.

[0041] The electromagnetic waves impinging on the scattering surface of the DCS can be generated by a transmitter (e.g., but not limited to).

[0042] The advantage of this is that the DCS is configured and controlled to generate electromagnetic waves based on the impinging waves, which can be applied to different scenarios, applications, and configurations. In other words, the radio frequency device provided by the present invention can configure the surface of the DCS in a controlled manner so as to manipulate the propagating electromagnetic waves impinging on the surface and scatter the impinging electromagnetic waves as expected, for example, scatter to an area of interest or to a target.

[0043] More advantageously, the radio frequency device provided by the present invention can directly generate compressed codewords using only a few parameters, thereby reducing the computational complexity and further reducing the codeword storage and exchange between different components in the radio frequency device. In addition, such compressed codewords can be regarded as explicitly eliminating the characteristics of the DCS, and thus a higher level of abstraction (i.e., a generalized version of the codeword) is obtained, which can be decompressed by considering the characteristics of the DCS, i.e., adapted to the DCS.

[0044] In the present invention, codeword generation refers to constructing and configuring the phase shift of each scattering element in the scattering elements of the DCS.

[0045] In one implementation of the second aspect, the characteristics of the electromagnetic waves impinging on the scattering surface of the DCS include at least one of the propagation vector and the structure of the electromagnetic waves impinging on the scattering surface of the DCS.

[0046] In one implementation of the second aspect, the characteristics of the desired electromagnetic waves scattered by the scattering surface of the DCS include at least one of the desired propagation vector and the structure of the desired electromagnetic waves scattered by the scattering surface of the DCS.

[0047] In one implementation of the second aspect, the one or more parameters of the DCS include at least one of the position of the DCS, the orientation of the DCS, the size of each scattering element in the scattering elements of the scattering surface of the DCS, and the total number of the scattering elements of the scattering surface of the DCS.

[0048] By simultaneously considering the characteristics of the electromagnetic waves impinging on the DCS, the characteristics of the desired electromagnetic waves scattered by the DCS, and the parameters of the DCS itself, all possible scenarios (near field and / or far field) can be considered when generating codewords.

[0049] In one implementation of the second aspect, the DCS controller is further configured to determine the characteristics of the electromagnetic wave impinging on the scattering surface of the DCS. Additionally or alternatively, the DCS controller is further configured to determine the characteristics of the desired electromagnetic wave scattered by the scattering surface of the DCS.

[0050] In one implementation of the second aspect, the DCS controller is further configured to: determine an optimal quadric surface Q based on a quadric surface Q that behaves as a perfect electric conductor (PEC), based on the characteristics of the electromagnetic wave impinging on the scattering surface of the DCS, and based on the characteristics of the desired electromagnetic wave scattered by the scattering surface of the DCS * , where the optimal quadric surface describes the transformation of the electromagnetic wave impinging on the scattering surface of the DCS to form the desired electromagnetic wave scattered by the scattering surface of the DCS; determine the phase shift of each scattering element in the scattering elements of the scattering surface of the DCS as a function of one or more parameters of the optimal quadric surface Q * .

[0051] In the present invention, codewords can be customized according to the reflection characteristics of the quadric surface and its parameters, which describe the required or desired transformation that the surface of the DCS is to apply to the electromagnetic wave impinging on the DCS, and then the behavior of the secondary reflection surface is mapped to the DCS. This mapping can include determining the phase shift of each scattering in the scattering elements of the surface of the DCS such that the wave scattered by the DCS can be the same as the wave reflected by a mirror having the shape of a quadric surface.

[0052] Therefore, the codewords can be compressed using the minimum number of parameters, which is at most the number of parameters defining the determined quadric surface. More advantageously, the generated codewords can encode the phase shifts that need to be individually applied to each of the scattering elements in the scattering elements of the DCS to form the desired electromagnetic wave scattered by the DCS.

[0053] Additionally, several codewords and a codebook (a set of codewords) can be generated on the fly according to a quadratic expression.

[0054] In one implementation of the second aspect, the canonical equation of the quadric surface Q is:

[0055] where a, b, c, d, α 1 , α 2 , β 1 , β 2 , γ 1 , γ2 and τ are parameters of the quadratic surface Q, and α 2 , β 2 , γ 2 , τ ∈ {0, 1}.

[0056] In an implementation manner of the second aspect, the DCS controller is further configured to determine, according to the minimum distance between the optimal quadratic surface Q * and the scattering surface of the DCS, the phase shift of each scattering element in the scattering elements of the scattering surface of the DCS.

[0057] In an implementation manner of the second aspect, the codeword indicates the determined phase shift of each scattering element in the scattering elements of the scattering surface of the DCS, so that using the codeword to control the scattering elements of the scattering surface of the DCS can scatter the electromagnetic wave hitting the DCS according to the reflection of the quadratic surface.

[0058] The third aspect of the present invention provides a radio frequency method. The radio frequency method includes: a transmitter emits an electromagnetic wave onto a scattering surface of a DCS, where the scattering surface includes a plurality of scattering elements, and each scattering element has a controllable phase shift; a DCS controller determines a codeword according to one or more parameters of the DCS, characteristics of the electromagnetic wave emitted by the transmitter, and characteristics of an expected electromagnetic wave scattered by the scattering surface of the DCS; the DCS controller uses the codeword to control the scattering elements of the scattering surface of the DCS to form the expected electromagnetic wave by scattering the electromagnetic wave emitted by the transmitter. The codeword determines a phase shift configuration of the plurality of scattering elements of the scattering surface of the DCS.

[0059] In an implementation manner of the third aspect, the characteristics of the electromagnetic wave emitted by the transmitter include at least one of a propagation vector and a structure of the electromagnetic wave emitted by the transmitter.

[0060] In an implementation manner of the third aspect, the characteristics of the expected electromagnetic wave scattered by the scattering surface of the DCS include at least one of an expected propagation vector and a structure of the expected electromagnetic wave scattered by the scattering surface of the DCS.

[0061] In an implementation manner of the third aspect, the one or more parameters of the DCS include at least one of a position of the DCS, a direction of the DCS, a size of each scattering element in the scattering elements of the scattering surface of the DCS, and a total number of the scattering elements of the scattering surface of the DCS.

[0062] By considering both the characteristics of the electromagnetic wave transmitted by the transmitter and the characteristics of the desired electromagnetic wave scattered by the DCS as well as the parameters of the DCS itself, all possible scenarios (near field and / or far field) can be considered when generating the codeword.

[0063] In one implementation of the third aspect, the method further includes: the DCS controller determines the characteristics of the electromagnetic wave transmitted by the transmitter, or obtains the characteristics of the electromagnetic wave transmitted by the transmitter through the signaling of the transmitter. Additionally or alternatively, the DCS controller determines the characteristics of the desired electromagnetic wave scattered by the scattering surface of the DCS, or the DCS controller obtains the characteristics of the desired electromagnetic wave scattered by the scattering surface of the DCS through the signaling of the transmitter.

[0064] The advantage of this is that the complexity can be reduced and the information exchange between different components in the radio frequency device can be decreased.

[0065] In one implementation of the third aspect, the positions of the transmitter and the DCS and their orientations are fixed relative to each other.

[0066] In one implementation of the third aspect, the method further includes: the DCS controller determines the optimal quadratic surface Q according to the quadratic surface Q that behaves as a perfect electric conductor (PEC), according to the characteristics of the electromagnetic wave transmitted by the transmitter, and according to the characteristics of the desired electromagnetic wave scattered by the scattering surface of the DCS * , where the optimal quadratic surface describes the transformation of the electromagnetic wave transmitted by the transmitter to form the desired electromagnetic wave scattered by the scattering surface of the DCS; the DCS controller determines the phase shift of each scattering element in the scattering surface of the DCS as a function of one or more parameters of the optimal quadratic surface Q * of.

[0067] In the present invention, the codeword can be customized according to the reflection characteristics of the quadratic surface and its parameters, which describe the required or desired transformation that the surface of the DCS is to apply to the electromagnetic wave transmitted to the DCS, and then the behavior of the secondary reflection surface is mapped to the DCS. This mapping can include determining the phase shift of each scattering in the scattering elements of the surface of the DCS such that the wave scattered by the DCS can be the same as the wave reflected by a mirror having the shape of a quadratic surface.

[0068] Thus, the codewords can be compressed using a minimum number of parameters, which is at most the number of parameters defining the determined quadric surface. More preferably, the generated codewords can encode the phase shifts that need to be individually applied to each of the scattering elements of the DCS to form the desired electromagnetic wave scattered by the DCS.

[0069] Additionally, several codewords and a codebook (a set of codewords) can be generated on the fly according to a quadratic expression.

[0070] In one implementation of the third aspect, the canonical equation of the quadric surface Q is:

[0071] where a, b, c, d, α 1 、α 2 、β 1 、β 2 、γ 1 、γ 2 and τ are parameters of the quadric surface Q, and α 2 、β 2 、γ 2 、τ ∈ {0, 1}.

[0072] In one implementation of the third aspect, the method further includes: the DCS controller determines the phase shift of each of the scattering elements of the scattering surface of the DCS according to the minimum distance between the optimal quadric surface Q * and the scattering surface of the DCS.

[0073] In one implementation of the third aspect, the codewords indicate the determined phase shifts of each of the scattering elements of the scattering surface of the DCS, such that using the codewords to control the scattering elements of the scattering surface of the DCS can scatter the electromagnetic wave emitted by the source according to the reflection of the quadric surface.

[0074] In one implementation of the third aspect, the method further includes: the desired electromagnetic wave scattered by the scattering surface of the DCS irradiates a target.

[0075] In one implementation of the third aspect, the method further includes: the target receives the desired electromagnetic wave scattered by the scattering surface of the DCS, where the target is a receiver.

[0076] In one implementation of the third aspect, the method further includes: the DCS controller obtains the characteristics of the desired electromagnetic wave scattered by the scattering surface of the DCS through the signaling of the target. Alternatively, the method includes: the DCS controller uses information about the target to obtain the characteristics of the desired electromagnetic wave scattered by the scattering surface of the DCS.

[0077] The method of the third aspect and its implementation achieve the same advantages as the device of the first aspect and its corresponding implementation described above.

[0078] A fourth aspect of the present invention provides a radio frequency method. The DCS includes the scattering surface, the scattering surface includes a plurality of scattering elements, and each scattering element has a controllable phase shift. The radio frequency method includes: the DCS controller determines a codeword according to one or more parameters of the DCS, according to the characteristics of the electromagnetic wave hitting the scattering surface of the DCS, and according to the characteristics of the desired electromagnetic wave scattered by the scattering surface of the DCS; the DCS controller uses the codeword to control the scattering elements of the scattering surface of the DCS to form the desired electromagnetic wave by scattering the electromagnetic wave hitting the scattering surface of the DCS. The codeword determines the phase shift configuration of the plurality of scattering elements of the scattering surface of the DCS.

[0079] The electromagnetic wave hitting the scattering surface of the DCS can be generated by (for example but not limited to) a transmitter.

[0080] The method of the fourth aspect and its implementation achieve the same advantages as the device of the second aspect and its corresponding implementation.

[0081] A fifth aspect of the present invention provides a computer program product including program code. When the program code is implemented on a processor, the program code is used to execute the method according to the third aspect or its implementation.

[0082] A sixth aspect of the present invention provides a computer program product including program code. When the program code is implemented on a processor, the program code is used to execute the method according to the fourth aspect or its implementation.

[0083] The solution provided by the present invention aims to provide a general systematic process for determining codewords, and provides the following advantages:

[0084] · A unique system framework applicable to all scenarios, applications, and configurations.

[0085] · Codewords and codebooks can be generated instantaneously according to quadratic expressions.

[0086] ·The compressed representations of the codewords and the codebook require only a few parameters instead of thousands of parameters.

[0087] ·The codewords are generated easily and quickly according to a quadratic expression.

[0088] ·The codewords are generated directly.

[0089] It should be noted that all the devices, elements, units and apparatuses described in this application can be implemented in software or hardware elements or any combination thereof. All the steps performed by the various entities described in this application and the functions described to be performed by the various entities are intended to indicate that the respective entities are adapted or used to perform their respective steps and functions. Although in the description of the following specific embodiments, the specific functions or steps performed by the external entities are not reflected in the description of the specific detailed elements of the entities performing the specific steps or functions, those skilled in the art should be clear that these methods and functions can be implemented by the corresponding software or hardware elements or any combination thereof. Description of the Drawings

[0090] In combination with the accompanying drawings, the description of the following specific embodiments will elaborate on the above aspects and their implementation manners.

[0091] Figure 1 Shows the radio frequency device provided by the present invention;

[0092] Figure 2 Shows an exemplary configuration of the scattering surface of the DCS;

[0093] Figure 3 Shows an exemplary flowchart for generating codewords provided by the present invention;

[0094] Figure 4 Shows an example of determining the phase shift of each scattering element in the scattering elements of the DCS;

[0095] Figure 5 Shows the exchange of information between the transmitter, the DCS controller and the scattering surface of the DCS;

[0096] Figure 6 Shows the radio frequency device provided by the present invention;

[0097] Figure 7 Shows the radio frequency device provided by the present invention;

[0098] Figure 8 Shows the exchange of information between the transmitter, the DCS controller, the scattering surface of the DCS and the target or the receiver;

[0099] Figure 9 (a) to (d) show examples of the desired electromagnetic waves scattered by one or more DCSs.

[0100] Figure 10 (a) and (b) show an example of the electromagnetic wave scattered by the surface of the DCS using a codeword for wave focusing applications and an example of the desired electromagnetic wave scattered by the surface of the DCS;

[0101] Figure 11 (a) and (b) show an example of the electromagnetic wave scattered by the surface of the DCS using a codeword for plane wave generation applications and an example of the desired electromagnetic wave scattered by the surface of the DCS;

[0102] Figure 12 (a) to (c) show examples of the desired electromagnetic waves scattered by two DCSs using multiple quadric surfaces.

[0103] Figure 13 Shows the method provided by the present invention for a radio frequency device. Detailed implementation

[0104] Figure 1 Shows an exemplary embodiment of the radio frequency device 100 provided by the present invention. The device 100 includes a DCS 102 having a scattering surface 104. The device 100 further includes a transmitter 108 and a DCS controller 112. The position of the transmitter 108 and the position and orientation of the DCS 102 can be fixed relative to each other. The scattering surface 104 of the DCS 102 includes a plurality of scattering elements 106. Each scattering element 106 of the scattering surface 104 has a controllable phase shift, which can be controlled by the DCS controller 112, as described below. In addition, the DCS controller 112 can be implemented as the DCS 102 or can be a part of the DCS 102, or can be implemented as the transmitter 108 or can be a part of the transmitter 108.

[0105] The transmitter 108 is used to transmit an electromagnetic wave 110 onto the scattering surface 104 of the DCS 102.

[0106] In the present invention, the terms "wave" and "wavefront" can be used interchangeably. In addition, the terms "electromagnetic signal" and "electromagnetic wave or wavefront" can also be used interchangeably.

[0107] The DCS controller 112 is used to determine a codeword 113 based on one or more parameters of the DCS 102, the characteristics of the electromagnetic wave 110 transmitted by the transmitter 108, and the characteristics of the desired electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102.

[0108] The codeword 113 determines the phase shift configuration of the plurality of scattering elements 106 of the scattering surface 104 of the DCS 102.

[0109] Then, the DCS controller 112 is used to control the scattering elements 106 of the scattering surface 104 of the DCS 102 using the codeword 113 to form a desired electromagnetic wave 114 by scattering the electromagnetic wave 110 that arrives at the scattering surface 104 of the DCS 102 emitted by the transmitter 108. Then, the desired electromagnetic wave 114 can reach the region of interest.

[0110] Generally speaking, in the present invention, the characteristics of the electromagnetic wave 110 emitted by the transmitter 108 considered by the DCS controller 112 when determining the codeword 113 are the characteristics of the electromagnetic wave 110 hitting the scattering surface 104 of the DCS 102, that is, the characteristics at the DCS 102.

[0111] That is to say, the characteristics of the electromagnetic wave 110 emitted by the transmitter 108 used by the DCS controller 112 are the characteristics perceived by the DCS 102 when the electromagnetic wave 110 reaches the scattering surface 104 of the DCS 102. This characteristic may not be consistent with the characteristics of the same electromagnetic wave 110 at the transmitter 108, that is, not consistent with the characteristics of the electromagnetic wave 110 generated at the transmitter 108. This is because the electromagnetic wave 110 generated by the transmitter 108 may undergo one or more changes when propagating through the channel between the transmitter 108 and the DCS 102. For example, it may change due to one or more physical obstacles located between the transmitter 108 and the DCS 102. Therefore, for the DCS controller 112, the relevant characteristics of the electromagnetic wave 110 are the characteristics that the electromagnetic wave 110 has when it reaches the scattering surface 104 of the DCS 102.

[0112] Optionally, the DCS controller 112 of the DCS 102 may consider the characteristics of the electromagnetic wave 110 generated at the transmitter 108. For example, by using a determined transfer function to determine the characteristics of the electromagnetic wave 110 at the scattering surface 104 of the DCS 102 (when the electromagnetic wave 110 hits the DCS 102), the transfer function taking into account the channel between the transmitter 108 and the DCS 102.

[0113] The characteristics of the electromagnetic wave 110 transmitted by the transmitter 108 may include at least one of the propagation vector and the structure of the electromagnetic wave 110 transmitted by the transmitter 108 sensed at the scattering surface 104 of the DCS 102. For example, the propagation vector may be derived from the angle of arrival (AoA) of the electromagnetic wave 110 transmitted by the transmitter 108 at the scattering surface 104 of the DCS 102. The AoA may also be calculated from the angle of departure (AoD) of the electromagnetic wave 110 transmitted by the transmitter 108 (when the electromagnetic wave 110 is generated at the transmitter 108) and other information (such as relative position and orientation). The structure of the electromagnetic wave 110 may include, for example, a plane wave or a spherical wave, which may correspond to a near-field scenario or a far-field scenario, respectively.

[0114] The characteristics of the desired electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102 may include at least one of the desired propagation vector and the structure of the desired electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102. For example, the desired propagation vector may be derived from the angle of departure (AoD) of the desired electromagnetic wave 114 obtained by scattering the electromagnetic wave 110 transmitted by the transmitter 108 through the surface 104 of the DCS 102. The structure of the desired electromagnetic wave 114 may include, for example, a plane wave or a spherical wave, which may correspond to a desired near-field scenario or a desired far-field scenario, respectively.

[0115] One or more parameters of the DCS 102 may include at least one of the position of the DCS 102, the orientation of the DCS 102, the size of each scattering element 106 of the scattering surface 104 of the DCS 102, and the total number of scattering elements 106 of the scattering surface 104 of the DCS 102.

[0116] Therefore, the radio frequency device 100 provided by the present invention can design a phase shift configuration (i.e., the codeword 113) for each scattering element 106 of the scattering surface 104 of the DCS 102, and can also use the phase shift configuration to control the surface 104 of the DCS 102 to form the electromagnetic wave 114 by scattering the electromagnetic wave 110 transmitted by the transmitter 108 as expected (e.g., for a specific application of the radio frequency device 100).

[0117] More preferably, since the codeword 113 can be determined by considering the characteristics of the electromagnetic wave 110 emitted by the transmitter, one or more parameters of the DCS itself, and the characteristics of the desired electromagnetic wave 114, the radio frequency device 100 provided by the present invention can operate in several possible scenarios. For example, it can operate in the near field or far field, and can be used for several applications, including beam focusing, single-user and multi-user focusing, or hologram generation, etc., and can be used in different technologies.

[0118] It should be noted that in the present invention, the scattering surface 104 of the DCS 102 can have different configurations. For example, as Figure 2 shown, the scattering surface 104 of the DCS 102 can have different shapes. For example, the scattering surface 104 can be planar or non-planar.

[0119] The codeword determination proposed by the present invention can be based on the reflection characteristics of a quadric surface. The DCS controller 112 can determine the codeword 113 by deriving the optimal quadric surface and its parameters. The optimal quadric surface can describe the transformation that the scattering surface 104 of the DCS 102 is to apply to the electromagnetic wave 110 emitted by the transmitter to obtain the desired electromagnetic wave 114. Then, the behavior of the reflection of the quadric surface can be mapped to the surface 104 of the DCS 102. This mapping can include determining the phase shift of each scattering element 106 on the surface 104 of the DCS 102 such that the desired electromagnetic wave 114 scattered by the DCS 102 can be the same as the electromagnetic wave 114 reflected by a PEC or a mirror having the shape of the optimal quadric surface, for example, a paraboloid of revolution or other quadric surface shapes in two-dimension (2D) or three-dimension (3D).

[0120] In the present invention, it is generally considered that the optimal quadric surface Q * can describe a transformation to form the desired electromagnetic wave 114 from the electromagnetic wave 110 impinging on the scattering surface 104 of the DCS 102.

[0121] That is to say, the DCS controller 112 can be used to determine the quadric surface Q, which is defined by the general expression in the canonical form given by Equation (1):

[0122]

[0123] where a, b, c, d, α 1 、α 2 、β 1 、β 2 、γ 1 、γ 2σ and τ are parameters of the quadric surface Q, α 2 , β 2 , γ 2 , τ ∈ {0, 1}. Therefore, the quadric surface is defined by the above 11 parameters.

[0124] The quadric surface Q given by Equation (1) is a general representation of the quadric surface shape, representing a large family of functions that include ellipses, parabolas, and hyperbolas in the 2D domain or hyperboloids, paraboloids, and ellipsoids in 3D.

[0125] In the present invention, the term "quadric surface" refers to both conic curves in 2D and quadric surfaces in 3D.

[0126] Then, in order to ensure that the scattering surface 104 of the DCS 102 can generate or approximately generate the desired electromagnetic wave 114 by scattering the electromagnetic wave 110, the quadric surface Q can be optimized. That is to say, by considering the characteristics of the electromagnetic wave 110 emitted by the transmitter 108, one or more parameters of the DCS 102, and the characteristics of the desired electromagnetic wave 114 scattered by the DCS 102, the optimal quadric surface Q * and its corresponding parameters can be obtained.

[0127] Once the optimal quadric surface Q * and its parameters are obtained, the phase shift of each scattering element in the scattering element 106 of the DCS 102 can be calculated to simulate the quadric surface behavior. For example, simulating the reflection performed by the optimal quadric surface Q * acting as a PEC.

[0128] That is to say, the phase shift configuration of the multiple scattering elements 106 of the scattering surface 104 of the DCS 102 is such that the scattered wave of the DCS surface 104 can simulate the reflection of the electromagnetic wave 110 as if this reflection is performed by the optimal quadric surface Q * acting. This can correspond to a morphism between two surfaces. For example, a morphism between the scattering surface 104 of the DCS 102 and the obtained optimal quadric surface Q * acting.

[0129] Based on the above, Figure 3 A flowchart for determining the codeword 113 provided by the present invention is shown, and this flowchart can be executed by the radio frequency device 100. Specifically, this flowchart can be executed by the DCS controller 112.

[0130] The DCS controller 112 can be used to determine the generalized quadric surface Q defined by Equation (1).

[0131] In step S502, the DCS controller can be used to determine the optimal quadratic surface Q based on the quadratic surface Q (which is represented as a PEC as described above), based on the characteristics of the electromagnetic wave 110 emitted by the transmitter 108, and based on the characteristics of the desired electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102. * The optimal quadratic surface describes the transformation of the electromagnetic wave 110 emitted by the transmitter 108 to form the desired electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102.

[0132] By determining the optimal quadratic surface Q * its corresponding parameters can also be determined by the DCS controller 112.

[0133] Then, in step S504, the DCS controller can be used to determine the phase shift of each scattering element 106 of the scattering surface 104 of the DCS 102 as a function of one or more parameters of the optimal quadratic surface Q * The determined phase shift of each scattering element 106 of the scattering surface 104 of the DCS 102 can be referred to as the phase shift configuration of the plurality of scattering elements 106.

[0134] Therefore, in step S506, the phase shift configuration (i.e., the codeword) of the plurality of scattering elements 106 of the scattering surface 104 of the DCS 102 can be obtained as a function of one or more parameters of the optimal quadratic surface Q * as an output.

[0135] Therefore, the codeword 113 can indicate the determined phase shift of each scattering element 106 of the scattering surface 104 of the DCS 102 such that using the codeword 113 to control the scattering elements 106 of the scattering surface 104 of the DCS 102 can scatter the electromagnetic wave 110 emitted by the transmitter 108 according to the reflection of the quadratic surface.

[0136] In other words, the codeword 113 can be used to design and calibrate the scattering elements 106 of the scattering surface 104 of the DCS 102 to scatter the electromagnetic wave 110 emitted by the transmitter 108 so as to form the desired electromagnetic wave 114.

[0137] The optimal quadratic surface Q * can be determined by solving the optimization problem given by equation (2) and other means:

[0138] Q * = arg min {Q*} (d(S {DCS的期望散射波} , S {Q的反射撞击波} )) (2)

[0139] Where:

[0140] S {DCS的期望散射波} is the equiphase surface of the desired electromagnetic wave 114 at the scattering surface 104 of the DCS 102.

[0141] S {Q的反射撞击波} is the equiphase surface of the wave obtained by reflecting from the quadratic surface Q after the electromagnetic wave 110 emitted by the transmitter 108 impinges on the virtual quadratic surface Q.

[0142] d(.,.) is the distance metric between two surfaces.

[0143] Estimate the quadratic surface Q * and its parameters can be simplified by using the well-known properties of quadratic surfaces in mathematics (e.g., the properties of ellipsoids, paraboloids, hyperboloids, etc.).

[0144] The optimal quadratic surface Q * with predefined properties can be stored in the DCS controller 112 for quick estimation of the optimal surface Q * and its parameters.

[0145] Alternatively, the optimization problem for determining Q * can be solved by calculating the transformation filter F(.) given by equation (3), which is defined as follows:

[0146]

[0147] where the input wave structure refers to the structure of the electromagnetic wave 110 emitted by the transmitter 108 that impinges on the virtual quadratic surface Q, and the output wave structure refers to the structure of the desired electromagnetic wave 114.

[0148] Solving for F is equivalent to estimating the parameters a, b, c, d, α * of the optimal quadratic function Q 1 α 2 β 1 β 2 γ 1 γ 2 and τ, which geometrically represent the effect of the filter F.

[0149] There are several mathematical tools that can be used to estimate these parameters. For example, curve fitting by surface gradient matching, which is a commonly used technique for feature tracking in 360° video scenes, is given by equation (4):

[0150]

[0151] In addition, equation (4) can be expressed as a minimization problem that can optimize the quadratic surface Q, given by equation (5):

[0152]

[0153] For another example, the optimal transport method can be used to obtain the optimal quadratic surface Q * , which solves for the overall distribution density of the electromagnetic wave.

[0154] It should be noted that in the exemplary method for obtaining the optimal quadratic surface Q * disclosed above, the electromagnetic wave 110 (emitted by the transmitter 108) hitting the (virtual) quadratic surface Q is typically considered.

[0155] Since the parameters of the optimal quadratic surface Q * determine the desired transformation to be applied to the surface 104 of the DCS 102, the optimal quadratic surface Q * and its corresponding 11 parameters can determine a compressed version of the phase shift configuration of the scattering elements 106 of the DCS 102, i.e., a compressed version of the codeword 113, which is independent of the size of the DCS 102 and one or more parameters and the total number of the scattering elements 106 of the scattering surface 104 of the DCS 102.

[0156] In addition, it should be noted that in order to obtain the unique solution of the optimal quadratic surface Q * , its 11 parameters may be required. Nevertheless, a relaxed version of the optimal quadratic surface Q * with 10 parameters can also be used, because the offset (or scaling) version of the above optimal quadratic surface Q * has the same effect on the phase shift of the scattering elements 106, but differs by a modulus factor. Discarding the parameter d can achieve relaxation, thus providing a family of possible solutions for the optimal quadratic surface Q * .

[0157] Therefore, the parameters of the optimal quadratic surface Q * can determine the general representation of the codeword 113 in a given scenario. In different scenarios corresponding to different transmitted electromagnetic waves 110 and / or different desired scattered waves 114, different optimal quadratic surfaces Q * can be obtained to determine different codewords in different scenarios. Different scenarios can correspond to the same or different applications, but the common point is to determine the codeword through the parameters of the quadratic surface. Aggregating a set of codewords can determine a codebook obtained for an intended application and / or a set of intended applications.

[0158] Table 1 shows an example of codebook construction. Given a list of M desired transformations to be applied to the electromagnetic wave 110, the codebook including the codeword 113 can be indexed as shown in Table 1. The codeword 113 performs the desired transformation on the electromagnetic wave 110 transmitted by the transmitter 108 to form the corresponding desired electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102.

[0159]

[0160] Table 1: Example of a codebook using the proposed quadric surface parameter representation

[0161] In this example, the codebook can include a first entry that includes a first codeword 113 with an index that can be 1 and the parameters of the corresponding optimal quadric surface Q * which can be the parameters {a 1 , b 1 , c 1 , d 1 , α 1,1 , α 2,1 , β 1,1 , β 2,1 , γ 1,1 , γ 2,1 , τ 1} etc. The first phase shift configuration can form the first desired electromagnetic wave 114 by scattering the electromagnetic wave 110 transmitted by the transmitter. In addition, the codebook can include a second entry that includes a second codeword 113 with an index of 2 and the parameters of the corresponding optimal quadric surface Q * which are exemplarily the parameters {a 2 , b 2 , c 2 , d 2 , α 1,2 , α 2,2 , β 1,2 , β 2,2 , γ 1,2 , γ 2,2 , τ 2} of the second phase shift configuration of the scattering element 106 of the DCS 102. The second phase shift configuration can form the second desired electromagnetic wave 114, and so on until the codebook includes M codewords 113 that determine the M desired transformations to be applied to the electromagnetic wave 110.

[0162] In addition, since the codeword 113 can be specified as a function of the parameters of the corresponding optimal quadric surface Q * each of the M codewords 113 in Table 1 can be customized for different types of applications of the radio frequency device 100.

[0163] Thus, determining the codeword 113 according to the quadric model of the scattering surface 104 of the DCS 102 provided by the present invention can not only provide a low-cost feedback mechanism for the configuration of the DCS 102 for a specific application located at a known position in space, but also provide great generality, because as long as one or more parameters of any DCS 102 are known, the codeword can be easily adapted to any DCS 102.

[0164] The DCS controller 112 can also be used to determine the phase shift of each scattering element 106 of the scattering surface 104 of the DCS 102 according to the optimal quadric Q * and the minimum distance between the scattering surface 104 of the DCS 102.

[0165] Figure 4 An exemplary manner of determining the phase shift of each scattering element 106 of the scattering surface 104 of the DCS 102 provided by the present invention is shown. In Figure 4 , a representation of the radio frequency device 100 is shown, which is obtained on a cutting plane that includes the propagation vector of the electromagnetic wave 110 emitted by the transmitter 108 and the propagation vector of the desired electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102, as well as a given point M representing the scattering element of the scattering surface 104 of the DCS 102 k . In this example, it is considered that the optimal quadric Q * is uniquely defined and tangent to the scattering surface 104 of the DCS 102.

[0166] When determining the unique optimal quadric Q * , the phase shift of each scattering element 106M k can be calculated as the compensation between the quadric Q * and the surface spanned by the scattering element 106 downsampled to the corresponding position in the actual scattering surface 104 of the DCS 102.

[0167] In this method, the distance can be determined according to the optimal quadric Q * (taking into account a scaling factor) and according to the propagation constants of the electromagnetic wave 110 emitted by the transmitter 108 and the desired electromagnetic wave 114, which are interpreted as phases.

[0168] Generally, the phase shift of the k-th scattering element 106 located at the point M k of the scattering surface 104 of the DCS 102 can be determined according to Equation (6):

[0169]

[0170] wherein

[0171]

[0172] wherein

[0173] · is the phase of the electromagnetic wave scattered from the scattering element located at point M after the electromagnetic wave 110 emitted by the transmitter 108 impinges on the DCS 102 and scatters from point M k k at the phase at

[0174] · is the phase of the desired scattered electromagnetic wave 114

[0175] · is the desired propagation vector of the desired electromagnetic wave 114

[0176] · is the propagation vector of the desired electromagnetic wave 114 observed at point M k

[0177] · is the straight line passing through the point of interest M on the scattering surface 104 of the DCS 102 k whose direction is determined by the propagation vector determined, · represents the set of points generated by the intersection of the optimal quadric surface Q * and the straight line

[0178] · is the point on the quadric surface Q * closest to the scattering surface 104 of the DCS 102, which conforms to the wave structure of the desired electromagnetic wave 114 and is in the set

[0179] set

[0180] The above and Figure 4 The example described can correspond to the morphism calculation of multi-point phase determination, i.e., the morphism between two surfaces in 3D, for example, the morphism between the scattering surface 104 of the DCS 102 and the optimal quadric surface Q *

[0181] In addition, an exemplary way to determine the phase shift of each scattering element in the scattering element 106 of the DCS 102 can be implemented in several ways, for example, by using a ray construction method or by using a path difference calculation, etc.

[0182] ​​​​​​​The DCS controller 112 may include a processor or processing circuitry (not shown) for performing, conducting, or initiating the various operations of the DCS controller 112 described herein. The processing circuitry may include hardware and / or the processing circuitry may be controlled by software. The hardware may include analog circuitry or digital circuitry, or both analog and digital circuitry. The digital circuitry may include components such as an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a digital signal processor (DSP), or a general-purpose processor. The DCS controller 112 may also include a storage circuitry that stores one or more instructions executable by the processor or the processing circuitry (specifically, under the control of the software). For example, the storage circuitry may include a non-transitory storage medium storing executable software code that, when executed by the processor or the processing circuitry, performs the various operations of the DCS controller 112.

[0183] Figure 5 An example of signaling exchange in the Figure 1 radio frequency device 100 is shown. Specifically, Figure 5 the example may describe a scenario in which the radio frequency device 100 includes a transmitter 108, a DCS controller 112, and a DCS 102 including a scattering surface 104 and a plurality of scattering elements 106. These entities may be collocated.

[0184] The DCS controller 112 may be used to determine the characteristics of the electromagnetic wave 110 transmitted by the transmitter 108, or may be used to obtain the characteristics of the electromagnetic wave 110 transmitted by the transmitter 108 through the signaling of the transmitter 108.

[0185] In addition, the DCS controller 112 may be used to: determine the characteristics of the desired electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102, or obtain the characteristics of the desired electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102 through the signaling of the transmitter 108.

[0186] The characteristics of the desired electromagnetic wave 114 may alternatively be predefined in the DCS controller 112, as it depends on the intended application of the radio frequency device 100, or may be determined by a priori estimation performed at the transmitter 108.

[0187] Thus, the transmitter 108 can directly or indirectly provide the propagation vector and / or structure of the electromagnetic wave 110 transmitted by the transmitter 108 to the DCS controller 112. Additionally, the transmitter 108 can also directly or indirectly provide the desired propagation vector and / or structure of the desired electromagnetic wave 114 to the DCS controller 112.

[0188] Furthermore, the DCS controller 112 can be used to obtain one or more parameters of the DCS 102 through the signaling of the scattering surface 104 of the DCS 102 or the signaling of the DCS itself. Alternatively, one or more parameters of the DCS 102 can be predefined in the DCS controller 112.

[0189] Then, the DCS controller 112 can determine the codeword 113. To determine the codeword 113, the DCS controller can also be used to determine the optimal quadric surface Q according to the quadric surface Q that behaves as a PEC, according to the characteristics of the electromagnetic wave 110 transmitted by the transmitter 108, and according to the characteristics of the desired electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102 * , where the optimal quadric surface describes the transformation of the electromagnetic wave 110 transmitted by the transmitter 108 to form the desired electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102. Additionally, the DCS controller can be used to determine the phase shift of each scattering element 106 of the scattering surface 104 of the DCS 102 as a function of one or more parameters of the optimal quadric surface Q * .

[0190] Then, the DCS controller 112 can control the configuration of the scattering surface 104 of the DCS 102 using the determined codeword 113 through a configuration signal, which is sent to the scattering surface 104 of the DCS 102 through the signaling of the DCS controller 112. That is, the DCS controller can be used to control the scattering elements 106 of the scattering surface 104 of the DCS 102 by sending the codeword 113 to the scattering surface 104 using the codeword 113.

[0191] The DCS controller 112 can also be used to send the codeword 113 to the transmitter 108 through signaling.

[0192] Once the codeword 113 is determined, the transmitter 108 can be used to start transmitting the electromagnetic wave 110 onto the scattering surface 104 of the DCS 102.

[0193] Figure 6 An exemplary embodiment of the radio frequency device 100 is shown, which is based on the radio frequency device 100 shown Figure 1 . The same elements are labeled with the same reference numerals.

[0194] InFigure 6 In the radio frequency device 100, the transmitter 108 can be an electromagnetic wave source. That is to say, the radio frequency device 100 can include a source 109, and the source 109 is used to transmit an electromagnetic wave 110 onto the scattering surface 104 of the DCS 102. The source 109 can be a natural source or any other type of electromagnetic wave source.

[0195] Therefore, the DCS controller 112 can be used to determine a codeword 113 based on one or more parameters of the DCS 102, the characteristics of the electromagnetic wave 110 transmitted by the source 109, and the characteristics of the desired electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102. The codeword 113 determines the phase shift configuration of a plurality of scattering elements 106 of the scattering surface 104 of the DCS 102. Then, the DCS controller 112 can also be used to control the scattering elements 106 of the scattering surface 104 of the DCS 102 using the codeword 113 to form the desired electromagnetic wave 114 by scattering the electromagnetic wave 110 transmitted by the source 109.

[0196] In this exemplary embodiment, the characteristics of the electromagnetic wave 110 transmitted by the source 109 that the DCS controller 112 considers when determining the codeword 113 represent the characteristics of the electromagnetic wave 110 impinging on the scattering surface 104 of the DCS 102.

[0197] This characteristic of the electromagnetic wave 110 (transmitted by the source 109) that the DCS 102 perceives when the electromagnetic wave 110 reaches the scattering surface 104 may not be consistent with the characteristics of the electromagnetic wave 110 generated at the source 109. This is because the electromagnetic wave 110 transmitted by the source 109 may undergo one or more changes when propagating through the channel between the source 109 and the DCS 102. For example, it may change due to one or more physical obstacles located between the source 109 and the DCS 102.

[0198] Optionally, the DCS controller 112 can consider the characteristics of the electromagnetic wave 110 generated at the source 109. For example, the DCS controller 112 can use a transfer function to determine the characteristics of the electromagnetic wave 110 at the scattering surface 104 of the DCS 102, and this transfer function can consider the channel between the source 109 and the DCS 102.

[0199] The characteristics of the electromagnetic wave 110 transmitted by the source 109 can include at least one of the propagation vector and the structure of the electromagnetic wave 110 transmitted by the source 109 perceived at the scattering surface 104 of the DCS 102.

[0200] The characteristics of the desired electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102 may include at least one of the desired propagation vector and structure of the desired electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102. One or more parameters of the DCS 102 may include at least one of the position of the DCS 102, the orientation of the DCS 102, the size of the scattering elements in the scattering elements 106 of the scattering surface 104 of the DCS 102, and the total number of the scattering elements 106 of the scattering surface 104 of the DCS 102.

[0201] The DCS controller 112 may also be used to determine the characteristics of the electromagnetic wave 110 transmitted by the source 109. Additionally or alternatively, the DCS 102 controller 112 may also be used to determine the characteristics of the desired electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102.

[0202] The position of the source 109 and the position and orientation of the DCS 102 may be fixed relative to each other.

[0203] The DCS controller 112 may also be used to determine the optimal quadratic surface Q according to the quadratic surface Q that behaves as a perfect electric conductor (PEC), according to the characteristics of the electromagnetic wave 110 transmitted by the source 109, and according to the characteristics of the desired electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102. * The optimal quadratic surface describes the transformation of the electromagnetic wave 110 transmitted by the source 109 to form the desired electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102. Then, the DCS controller 112 may be used to determine the phase shift of each scattering element in the scattering elements 106 of the scattering surface 104 of the DCS 102 as a function of one or more parameters of the optimal quadratic surface Q. *

[0204] In this exemplary embodiment, the optimal quadratic surface Q * may describe a transformation to form the desired electromagnetic wave 114 from the electromagnetic wave 110 impinging on the scattering surface 104 of the DCS 102.

[0205] The canonical equation and corresponding parameters of the quadratic surface Q are shown in Equation (1).

[0206] The DCS controller 112 may also be used to determine the phase shift of each scattering element in the scattering elements 106 of the scattering surface 104 of the DCS 102 according to the minimum distance between the optimal quadratic surface Q and the scattering surface 104 of the DCS 102. *

[0207] The codeword 113 can indicate a determined phase shift for each of the scattering elements 106 of the scattering surface 104 of the DCS 102, such that the scattering elements 106 of the scattering surface 104 of the DCS 102 can be controlled using the codeword 113 to scatter the electromagnetic wave 110 transmitted by the source 109 according to the reflection of the quadric surface.

[0208] By considering the electromagnetic wave 110 transmitted by the source 109 that impinges on the quadric surface Q (additionally or alternatively impinges on the scattering surface 104 of the DCS 102), the exemplary method for obtaining the optimal quadric surface Q Figure 1 disclosed for the exemplary embodiment of * and the phase shift for each of the multiple scattering elements 106 of the scattering surface 104 of the DCS 102 can equally apply to Figure 6 the exemplary embodiment of

[0209] In another exemplary embodiment, the radio frequency device 100 provided by the present invention may neither include the transmitter 108 nor the source 109. That is, the radio frequency device 100 may include the DCS 102 and the DCS controller 112. The DCS 102 includes a scattering surface 104, and the scattering surface 104 includes multiple scattering elements 106, and each scattering element 106 has a controllable phase shift.

[0210] The DCS controller 112 can be used to determine the codeword 113 according to one or more parameters of the DCS 102, the characteristics of the electromagnetic wave 110 impinging on the scattering surface 106 of the DCS, and the characteristics of the desired electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102. The codeword 113 can determine the phase shift configuration of the multiple scattering elements 106 of the scattering surface 104 of the DCS 102. In addition, the DCS controller 112 can be used to control the scattering elements 106 of the scattering surface 104 of the DCS 102 using the codeword 113 to form the desired electromagnetic wave 114 by scattering the electromagnetic wave 110 impinging on the scattering surface 104 of the DCS 102.

[0211] The electromagnetic wave 110 impinging on the scattering surface 104 of the DCS 102 can be generated by (such as but not limited to) any type of unknown source or transmitter, etc.

[0212] Figure 7 An exemplary embodiment of the radio frequency device 100 provided by the present invention is shown, and this exemplary embodiment is based on Figure 1 the radio frequency device 100 shown. The same elements are labeled with the same reference numerals.

[0213] Figure 7The radio frequency device 100 further includes a target 116 irradiated by an expected electromagnetic wave 114 scattered by a scattering surface 104 of the DCS 102. Specifically, the target may be a receiver 116, and the receiver 116 is configured to receive the expected electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102.

[0214] The DCS controller 112 may be implemented as the DCS 102 or may be a part of the DCS 102. Alternatively, the DCS controller 112 may be implemented as the transmitter 108 or may be a part of the transmitter 108. Further alternatively, the DCS controller 112 may be implemented as the target / receiver 116 or may be a part of the target / receiver 116.

[0215] Then, the DCS controller 112 is configured to determine a codeword 113 based on one or more parameters of the DCS 102, characteristics of the electromagnetic wave 110 transmitted by the transmitter 108, and characteristics of the expected electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102.

[0216] In addition, the DCS controller 112 is configured to use the codeword 113 to control the scattering elements 106 of the scattering surface 104 of the DCS 102 to form the expected electromagnetic wave 114 by scattering the electromagnetic wave 110 transmitted by the transmitter 108.

[0217] The DCS controller 112 is further configured to obtain characteristics of the expected electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102 by using information about the target / receiver 116. Alternatively, the DCS controller may obtain the characteristics of the expected electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102 through signaling of the target / receiver 116.

[0218] In Figure 7 the radio frequency device 100, the transmitter 108 may be an electromagnetic wave source configured to send the electromagnetic wave 110 onto the scattering surface 104 of the DCS 102, as Figure 6 the example discloses. The source may be a natural source or any other type of electromagnetic wave source.

[0219] Figure 8 Illustrated is an example of Figure 7 signaling exchange in the radio frequency device 100. Figure 8 The example may describe a scenario in which the radio frequency device 100 includes a transmitter 108, a DCS controller 112, a DCS 102 including a scattering surface 104, and a target or receiver 116. These entities may be collocated.

[0220] Figure 8 The example of Figure 5is the same as the example, except that in Figure 8 the DCS controller 112 can obtain the characteristics of the desired electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102 through the signaling of the target / receiver 116. Alternatively, the DCS controller 112 can use the information about the target / receiver 116 to obtain the characteristics of the desired electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102. Additionally, the characteristics of the desired electromagnetic wave 114 can alternatively be determined by prior estimation at the target or by applying reciprocity in the case where reverse path communication can be carried out between the transmitter 108 and the receiver 116.

[0221] According to the characteristics of the quadratic surface Q, the radio frequency device 100 provided by the present invention can be used for several applications. Additionally, the mathematical characteristics of the generalized quadratic surface Q given by Equation (1) can be used to reduce the number of parameters of the quadratic surface Q for determining the codeword 113, thereby reducing the complexity of determining the optimal quadratic surface Q * and its parameters as well as the phase shift of the scattering elements 106 of the DCS 102.

[0222] Exemplary applications of the radio frequency device 100 are as Figure 9 (a) to Figure 9 (d) shown. For clarity, the DCS controller 112 is not shown in the figures. These exemplary applications can include ray focusing (see Figure 9 (a)), ray diffraction (see Figure 9 (b)), ray parallelization (plane wave generation) (see Figure 9 (c)) and antenna aperture enhancement based on the combination of more than one DCS (exemplary DCSs 102 and 102a) (see Figure 9 (d)).

[0223] Figure 10 (b) depicts Figure 7 an exemplary use of the radio frequency device 100 for wave focusing. For clarity, the DCS controller 112 is not shown in the figure.

[0224] In Figure 10 (b)'s example, the target 116 can in particular be the receiver 116, and the positions of the transmitter 108 and the receiver 116 are fixed relative to each other. The DCS controller 112 can be used to determine the codeword 113 of the DCS 102 to maximize the energy received at the position of the receiver 116, i.e., to focus the electromagnetic wave 110 transmitted by the transmitter 108 onto the receiver 116 through the DCS 102.

[0225] Figure 10(a) describes the electromagnetic wave scattered by the scattering surface 104 of the DCS 102, which can be obtained in natural propagation and reflection scenarios, that is, without using the codeword 113. This electromagnetic wave follows the Snell-Descartes law of the antenna aperture Ω of the transmitter 108 and may not be focused onto the receiver 116 as expected.

[0226] Then, the DCS controller 112 can determine the codeword 113 based on one or more parameters of the DCS 102, the characteristics of the electromagnetic wave 110 transmitted by the transmitter 108, and the characteristics of the desired electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102. Then, the DCS controller can use the codeword 113 to control the scattering elements 106 of the scattering surface 104 of the DCS 102 to form the desired electromagnetic wave 114 by scattering the electromagnetic wave 110 transmitted by the transmitter 108, that is, the electromagnetic wave focused onto the receiver 116. Figure 10 (b) describes this.

[0227] In this exemplary application, the structure of the electromagnetic wave 110 transmitted by the transmitter 108 can be a cylindrical cone with a numerical aperture of Ω. The DCS controller 112 can obtain the structure of the electromagnetic wave 110 through the position of the transmitter 108 and its antenna aperture.

[0228] The structure of the desired electromagnetic wave 114 scattered by the DCS 102 can include a wavefront that should be in-phase focused on a specific point in space on the receiver 116. Therefore, the DCS controller 112 can obtain the desired characteristics of the desired electromagnetic wave 114 scattered by the DCS 102 through the signaling of the receiver 116, that is, the desired focusing of the electromagnetic wave 110 on the receiver 116. Alternatively, the DCS controller 112 can use information about the receiver 116 (e.g., the position of the receiver 116) to obtain the characteristics of the desired electromagnetic wave 114.

[0229] In addition, one or more parameters of the DCS 102 can include at least one of the position of the DCS 102, the size of each scattering element of the scattering elements 106 of the scattering surface 104 of the DCS 102, and the total number of the scattering elements 106 of the scattering surface 104 of the DCS 102.

[0230] To determine the codeword 113, the DCS controller 112 can determine the optimal quadratic surface Q based on the quadratic surface Q that behaves as a PEC, the characteristics of the electromagnetic wave 110 transmitted by the transmitter 108, and the characteristics of the desired electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102. *, this optimal quadratic surface describes the transformation of the electromagnetic wave 110 emitted by the transmitter 108 to form the desired (focused) electromagnetic wave 114 scattered by the DCS 102.

[0231] In Figure 10 (b) In an exemplary application, the DCS controller can determine a quadratic surface Q with two foci, which is obtained by rotating an ellipsoid or ellipsoid with foci Tx (transmitter 108) and Rx (receiver 116) and is tangent to the DCS 102. Such a rotational ellipsoid is obtained from the generalized canonical equation (Equation (1)) of the quadratic surface Q, and the parameter values of this equation are α 1 = β 1 = β 1 = 2, α 2 = β 2 = γ 2 = τ = 0, d = 1, b = c, and the canonical form of this rotational ellipsoid is given by Equation (8):

[0232]

[0233] The DCS controller 112 can further optimize the rotational ellipsoid (8) according to the characteristics of the electromagnetic wave 110 emitted by the transmitter 108 and according to the characteristics of the desired electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102, thereby generating an optimal quadratic surface Q with corresponding parameters * .

[0234] The DCS controller 112 can determine the optimal quadratic surface Q in the following ways * : Use an analytical method such as solving the gradient of the desired quadratic surface (generating the desired electromagnetic wave 114), and further fit this gradient with the gradient of the canonical expression of the quadratic surface Q given by Equation (1).

[0235] For another example, the DCS controller 112 can use a geometric construction method to determine the optimal quadratic surface Q according to the characteristics of the electromagnetic wave 110, one or more parameters of the DCS 102, and the desired application * , and this geometric construction method takes into account the characteristics of quadratic surfaces well-known in mathematics, for example, the characteristics of ellipsoids, paraboloids, or hyperboloids.

[0236] Then, the DCS controller 112 can determine the phase shift of each scattering element in the scattering element 106 of the scattering surface 104 of the DCS 102 according to the minimum distance between the optimal quadratic surface Q * and the scattering surface 104 of the DCS 102, as a function of one or more parameters of the optimal quadratic surface Q * .

[0237] In this example, the general equation for the phase shift of the k-th scattering element 106 of the DCS 102 given by Equation (6) can be written as Equation (9):

[0238]

[0239] where is the phase of the electromagnetic wave 110 observed at point M on the scattering surface 104 of the DCS 102 emitted from point Tx by the transmitter 108 k ; is the phase of the desired electromagnetic wave 114 scattered from point M k and received at point Rx of the receiver 116; is the phase of the electromagnetic wave 110 observed at point * on the optimal quadric surface Q emitted from point Tx by the transmitter 108 ; is the phase of the electromagnetic wave received at point Rx of the receiver 116 reflected from .

[0240] The phase shift of the k-th scattering element 106 of the DCS 102 satisfies the focusing requirement and exhibits as the optimal rotational ellipsoidal surface Q * , and can be obtained by the following method:

[0241]

[0242] where a is the parameter of the optimal quadric surface Q * , M k represents the position of the k-th scattering element 106 of the DCS 102, represents the vector between two points A and B, and ||.|| is the Euclidean norm operator.

[0243] In addition, the DCS controller 112 is used to control the scattering element 106 of the scattering surface 104 of the DCS 102 using the codeword 113 to form the desired electromagnetic wave 114 by scattering the electromagnetic wave 110 emitted by the transmitter 108, so as to implement Figure 10 the exemplary application of (b).

[0244] Figure 11 (b) shows Figure 1 or Figure 7 another exemplary use of the radio frequency device 100 for plane wave generation. In other words, Figure 11 the example of (b) aims to parallelize the rays of the electromagnetic wave 114 scattered by the DCS 102. In contrast, Figure 11(a) shows an exemplary electromagnetic wave scattered by the DCS 102, where the scattering surface 104 of the DCS 102 is not optimized, i.e., the codeword 113 is not used. In Figure 11 (a) and Figure 11 (b), for clarity, the DCS controller 112 is not shown in the figure.

[0245] In Figure 11 (b), the position of the surface 104 of the DCS 102 may be known and may be fixed relative to the transmitter 108. Additionally, one or more parameters of the DCS 102 may include at least one of the position of the DCS 102, the orientation of the DCS 102, the size of each scattering element 106 of the scattering surface 104 of the DCS 102, and the total number of scattering elements 106 of the scattering surface 104 of the DCS, and may be preset or predefined in the DCS controller 112.

[0246] In this exemplary application, the structure of the electromagnetic wave 110 emitted by the transmitter 108 may be a spherical wave or a plane wave defined in a cylindrical cone with a numerical aperture of Ω. The DCS controller 112 may obtain the structure of the electromagnetic wave 110 through the position of the transmitter 108 and its antenna aperture.

[0247] The structure of the desired electromagnetic wave 114 scattered by the DCS 102 may include an equiphase plane wave perpendicular to the propagation direction and parallel rays that may be required for the desired electromagnetic wave 114 to illuminate a target, which may be placed in the region of interest. The DCS controller 112 may obtain the desired characteristics of the desired electromagnetic wave 114 scattered by the DCS 102 through the signaling of the transmitter 108. Alternatively, the DCS controller 112 may use information about the region of interest (e.g., the position of the region of interest relative to the DCS 102 and / or the position relative to the position of the transmitter 108) to obtain the characteristics of the desired electromagnetic wave 114.

[0248] Furthermore, one or more parameters of the DCS 102 may include at least one of the position of the DCS 102, the size of each scattering element 106 of the scattering surface 104 of the DCS 102, and the total number of scattering elements 106 of the scattering surface 104 of the DCS 102.

[0249] Given the known position of the transmitting antenna 108 and the fixed antenna aperture Ω, the quadratic surface Q of the desired electromagnetic plane wave 114 scattered by the DCS 102 onto the region of interest may be a paraboloid of revolution.

[0250] This optimal paraboloid of revolution Q *can be obtained through the general canonical form of the quadric surface (Equation (1)), where the parameter values of the equation are α 1 = β 1 = 2, γ 1 = γ 2 = c = 1, α 2 = β 2 = d = τ = 0, This optimal paraboloid of revolution is represented in canonical form in Equation (11):

[0251]

[0252] where p is the minimum distance from the focus of the paraboloid to its directrix.

[0253] To achieve uniqueness, the elliptic paraboloid shown in Figure 11 (b) with the focus at TX / RX (transmitter 108 / receiver 116) and tangent to the DCS 102 is considered, thus fixing p.

[0254] Then, the DCS controller 112 can optimize the paraboloid of revolution given by (10) according to the characteristics of the electromagnetic wave 110 emitted by the transmitter 108 and according to the characteristics of the desired electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102, thereby generating the optimal quadric surface Q * and its corresponding parameters.

[0255] In addition, the DCS controller 112 can determine the phase shift of each scattering element in the scattering elements 106 of the scattering surface 104 of the DCS 102 as a function of one or more parameters of the optimal quadric surface Q * .

[0256] In this example, for the optimal paraboloid surface Q * , the general equation of the phase shift of the k-th scattering element 106 of the DCS 102 given by Equation (6) can be written as Equation (12):

[0257]

[0258] where U and V are points belonging to the optimal paraboloid surface Q * and the region of interest, M k represents the position of the k-th scattering element 106 on the scattering surface 104 of the DCS 102, represents the vector between two points A and B, and ||.|| is the Euclidean norm operator.

[0259] Then, the DCS controller 112 can use the codeword 113 to control the scattering elements 106 of the scattering surface 104 of the DCS 102 to form a desired electromagnetic wave 114 by scattering the electromagnetic wave 110 emitted by the transmitter 108, thereby achieving Figure 11 The exemplary application of (b).

[0260] Figure 12 (a) to Figure 12 (c) illustrate other exemplary uses of the radio frequency device 100, where more than one quadric surface Q is used to generate the codeword 113. Figure 12 The example of (a) can be applied to antenna enhancement because it can actually increase the antenna aperture. Figure 12 The example of (b) can be applied to multi-source focusing at the position of the receiver 116. Figure 12 The example of (c) can be applied to antenna enhancement for hologram generation in bistatic mode.

[0261] In Figure 12 (a) to Figure 12 (c), the radio frequency device 100 is based on the radio frequency device 100 of Figure 7 and may also include an additional DCS 102a, where the additional DCS 102a includes a scattering surface 104a, and the scattering surface 104a includes a plurality of scattering elements 106a. In Figure 12 (a) to Figure 12 (c), for clarity, the DCS controller 112 is not shown in the figure.

[0262] In Figure 12 (a) to Figure 12 (c) of the examples described, one or more DCSs 102, 102a can be used for the propagation environment and can be combined together to achieve a specific desired propagation effect.

[0263] To generate the codeword 113, the DCS controller can combine multiple quadric surfaces Q or divide a single quadric surface Q into multiple quadric surfaces. This can make the design and estimation of the desired electromagnetic wave 114 easier by relaxing the constraints on the parameters required to describe the multiple quadric surfaces Q, especially making it more flexible for different applications.

[0264] Therefore, the DCS controller 112 can be used to use a segmentation method, which includes adding constraints where the electromagnetic wave scattered by the scattering surface 104 of the first DCS 102 matches the electromagnetic wave arriving at the scattering surface 104a of the second DCS 102a, as described below.

[0265] In Figure 12 (a) to Figure 12In an exemplary application of (c), the structure of the electromagnetic wave 110 emitted by the transmitter 108 can be a cylindrical cone with a numerical aperture of Ω. The DCS controller 112 can obtain the structure of the electromagnetic wave 110 through the position of the transmitter 108 and its antenna aperture, as well as through the position of the receiver 116 and its antenna aperture.

[0266] The structure of the desired electromagnetic wave 114 scattered by the first DCS 102 can include a plane wave. The DCS controller 112 can obtain the desired characteristics of the desired electromagnetic wave scattered by the DCS 102 through the signaling of the transmitter 108 or through the signaling of the receiver 116.

[0267] In addition, one or more parameters of each DCS in the first DCS 102 and the second DCS 102a can include at least one of the position of the corresponding DCS 102, 102a, the scattering elements 106, 106a of the corresponding scattering surfaces 104, 104a of the DCS 102, 102a, the size of each scattering element, and the total number of scattering elements 106, 106a.

[0268] The parabolic surface can meet the desired requirements according to the characteristics of the electromagnetic wave 110 emitted by the transmitter 108, the desired characteristics of the desired electromagnetic wave 114, and one or more parameters of the DCS 102, 102a.

[0269] Therefore, the DCS controller 112 can determine the first quadric surface Q that describes the transformation of the electromagnetic wave 110 emitted by the transmitter 108 to form the first desired electromagnetic wave scattered by the first DCS 102 1 , and can determine the second quadric surface Q that describes the transformation of the scattered first desired electromagnetic wave to form the second desired electromagnetic wave 114 scattered by the second DCS 102a 2 .

[0270] The first quadric surface Q 1 and the second quadric surface Q 2 can both be parabolic surfaces. Such parabolic surfaces can focus any electromagnetic wave from infinity (far field) to the corresponding focus, and can also enable any electromagnetic wave originating from their respective foci to propagate as if it comes from infinity (parallel waves).

[0271] The first optimal quadric surface and the second optimal quadric surface can both be given by Equation (13):

[0272]

[0273] where p iis the minimum distance from the focus of the quadratic surface i to its directrix, where i = 1, 2 represent the quadratic surfaces of the first DCS 102 and the second DCS 102a respectively.

[0274] To achieve uniqueness, a first paraboloid of revolution with the focus at TX (transmitter 108) and tangent to the first DCS 102 and a second paraboloid of revolution with the focus at RX (receiver 116) and tangent to the second DCS 102a are considered, thus fixing p 1 and p 2 .

[0275] Then, the DCS controller 112 can determine the first optimal quadratic surface 1 and Q 2 , according to one or more parameters of the first DCS 102 and the second DCS 102a, according to the characteristics of the electromagnetic wave 110 emitted by the transmitter 108, the characteristics of the expected electromagnetic wave scattered by the scattering surface 104 of the first DCS 102, and according to the characteristics of the expected electromagnetic wave 114 scattered by the second scattering surface 104a of the second DCS 102a and the second optimal quadratic surface These two optimal quadratic surfaces respectively describe the transformations to be applied by the first DCS 102 and the second DCS 102a to form the first expected electromagnetic wave and the second expected electromagnetic wave 114.

[0276] Then, the DCS controller 112 can use the codeword 113 to control the scattering elements 106, 106a of the first DCS 102 and the second DCS 102a to form the expected electromagnetic wave scattered by the first scattering surface 104 of the first DCS 102 and the expected electromagnetic wave 114 scattered by the scattering surface 104a of the second DCS 102.

[0277] According to the generalized form of the phase shift of Equation (6), the DCS controller 112 can then determine the phase shift of each scattering element in the scattering elements 106, 106a of the first DCS 102 and the second DCS 102a given by Equation (14) and Equation (15):

[0278]

[0279] where U i and V i are points belonging to the optimal paraboloid surface and the corresponding region of interest respectively, represents the position of the k-th scattering element 106 on the i-th DCS 102, 102a, where i = 1, 2, represents the vector between two points A and B, and ||.|| is the Euclidean norm operator.

[0280] Then, the DCS controller 112 can use the codeword 113 to control the scattering elements 106 of the scattering surface 104 of the first DCS 102 and the scattering elements 106a of the scattering surface 104a of the second DCS 102a to respectively form the first desired electromagnetic wave and the second desired electromagnetic wave 114 for Figure 12 (a) to Figure 12 (c) the described applications.

[0281] Figure 13 An exemplary embodiment of the radio frequency method 200 provided by the present invention is shown. The method 200 can be executed by the device 100 of Figure 1 and Figure 7 disclosed above.

[0282] The method 200 includes step S202: The transmitter 108 emits an electromagnetic wave 110 onto the scattering surface 104 of a digitally controllable scatterer (DCS) 102, where the scattering surface 104 includes a plurality of scattering elements 106, and each scattering element 106 has a controllable phase shift.

[0283] The method 200 further includes step S204: The DCS controller 112 determines the codeword 113 based on one or more parameters of the DCS 102, the characteristics of the electromagnetic wave 110 emitted by the transmitter 108, and the characteristics of the desired electromagnetic wave 114 scattered by the scattering surface 104 of the DCS 102, where the codeword 113 determines the phase shift configuration of the plurality of scattering elements 106 of the scattering surface 104 of the DCS 102. The codeword 113 determines the phase shift configuration of the plurality of scattering elements 106 of the scattering surface 104 of the DCS 102.

[0284] In addition, the method 200 includes step S206: The DCS controller 112 uses the codeword 113 to control the scattering elements 106 of the scattering surface 104 of the DCS 102 to form the desired electromagnetic wave 114 by scattering the electromagnetic wave 110 emitted by the transmitter 108.

[0285] The method 200 may further include operations according to the above exemplary embodiment of the radio frequency device 100. Therefore, the method 200 achieves the same advantages as the radio frequency device 100.

[0286] The present invention also provides a computer program product including program code. When the program code is implemented on a processor, the program code is used to execute Figure 13The method 200 shown. The computer program may be included in a computer-readable medium of the computer program product. The computer-readable medium may substantially include any memory, such as, for example, Read-Only Memory (ROM), Programmable Read-Only Memory (PROM), Erasable PROM (EPROM), flash memory, Electrically Erasable PROM (EEPROM), or a hard disk drive.

[0287] Another exemplary embodiment of the radio frequency method provided by the present invention may include: The DCS includes a scattering surface, the scattering surface includes a plurality of scattering elements, and each scattering element has a controllable phase shift. The DCS controller determines a codeword according to one or more parameters of the DCS, according to the characteristics of the electromagnetic wave impinging on the scattering surface of the DCS, and according to the characteristics of the desired electromagnetic wave scattered by the scattering surface of the DCS.

[0288] The method may further include: The DCS controller uses the codeword to control the scattering elements of the scattering surface of the DCS to form the desired electromagnetic wave by scattering the electromagnetic wave impinging on the scattering surface of the DCS. The codeword determines the phase shift configuration of the plurality of scattering elements of the scattering surface of the DCS.

[0289] The electromagnetic wave impinging on the scattering surface of the DCS may be generated by (e.g., but not limited to) a transmitter.

[0290] The present invention has been described in connection with various embodiments as examples and implementations. However, upon study of the drawings, the present invention, and the independent claims, those skilled in the art will be able to understand and implement other variations when implementing the claimed subject matter. In the claims as well as the specification, the word "comprising" does not exclude other elements or steps, and the quantifier "a" does not exclude a plurality. A single element or other unit may fulfill the functions of several entities or items described in the claims. Listing certain measures in mutually different dependent claims does not indicate that a combination of these measures cannot be used in an advantageous implementation.

Claims

1. A radio frequency device (100), characterized in that, comprising: a digitally controllable scatterer DCS (102), wherein the DCS (102) includes a scattering surface (104), the scattering surface (104) includes a plurality of scattering elements (106), and each of the scattering elements (106) has a controllable phase shift; a transmitter (108) for transmitting an electromagnetic wave (110) onto the scattering surface (104) of the DCS (102); a DCS controller (112) for: determining a codeword (113) based on one or more parameters of the DCS (102), characteristics of the electromagnetic wave (110) transmitted by the transmitter (108), and characteristics of a desired electromagnetic wave (114) scattered by the scattering surface (104) of the DCS (102), wherein the codeword (113) determines a phase shift configuration of the plurality of scattering elements (106) of the scattering surface (104) of the DCS (102); using the codeword (113) to control the scattering elements (106) of the scattering surface (104) of the DCS (102) to form the desired electromagnetic wave (114) by scattering the electromagnetic wave (110) transmitted by the transmitter (108).

2. The radio frequency device (100) according to claim 1, characterized in that, the characteristics of the electromagnetic wave (110) transmitted by the transmitter (108) include at least one of a propagation vector and a structure of the electromagnetic wave (110) transmitted by the transmitter (108).

3. The radio frequency device (100) according to claim 1 or 2, characterized in that, the characteristics of the desired electromagnetic wave (114) scattered by the scattering surface (104) of the DCS (102) include at least one of a desired propagation vector and a structure of the desired electromagnetic wave (114) scattered by the scattering surface (104) of the DCS (102).

4. The radio frequency device (100) according to any one of claims 1 to 3, characterized in that, the one or more parameters of the DCS (102) include at least one of a position of the DCS (102), a direction of the DCS (102), a size of each of the scattering elements (106) of the scattering surface (104) of the DCS (102), and a total number of the scattering elements (106) of the scattering surface (104) of the DCS (102).

5. The radio frequency device (100) according to any one of claims 1 to 4, characterized in that, the DCS controller (112) is further configured to: determine the characteristics of the electromagnetic wave (110) transmitted by the transmitter (108), or obtain the characteristics of the electromagnetic wave (110) transmitted by the transmitter (108) through signaling of the transmitter (108); and / or The DCS (102) controller (112) is further configured to: determine the characteristics of the desired electromagnetic wave (114) scattered by the scattering surface (104) of the DCS (102), or obtain the characteristics of the desired electromagnetic wave (114) scattered by the scattering surface (104) of the DCS (102) through signaling of the transmitter (108).

6. The radio frequency device (100) according to any one of claims 1 to 5, wherein, the positions of the transmitter (108) and the DCS (102) and their orientations are fixed relative to each other.

7. The radio frequency device (100) according to any one of claims 1 to 6, wherein, the DCS controller (112) is further configured to: An optimal quadric surface Q is determined based on a quadric surface Q that behaves as a perfect electric conductor PEC, based on the characteristics of the electromagnetic wave (110) emitted by the emitter (108), and based on the characteristics of the desired electromagnetic wave (114) scattered by the scattering surface (104) of the DCS (102). * wherein the optimal quadric surface describes a transformation of the electromagnetic wave (110) emitted by the emitter (108) to form the desired electromagnetic wave (114) scattered by the scattering surface (104) of the DCS (102); Determine the phase shift of each of the scattering elements of the scattering surface (104) of the DCS (102) as a function of one or more parameters of the optimal quadric surface Q * .

8. The radio frequency device (100) according to claim 7, wherein, the canonical equation of the quadratic surface Q is: Among them, a, b, c, d, α 1 , α 2 , β 1 , β 2 , γ 1 , γ 2 and τ are parameters of the quadratic surface Q, α 2 , β 2 , γ 2 , τ ∈ {0, 1}.

9. The radio frequency device (100) according to claim 7, wherein, The DCS controller (112) is further configured to determine, according to the minimum distance between the optimal quadratic surface Q * and the scattering surface (104) of the DCS (102), the phase shift of each scattering element of the scattering elements (106) of the scattering surface (104) of the DCS (102).

10. The radio frequency device (100) according to any one of claims 7 to 9, wherein, the codeword (113) indicates the determined phase shift of each scattering element of the scattering elements (106) of the scattering surface (104) of the DCS (102), such that using the codeword (113) to control the scattering elements (106) of the scattering surface (104) of the DCS (102) can scatter the electromagnetic wave (110) emitted by the transmitter (108) according to the reflection of the quadratic surface.

11. The radio frequency device (100) according to any one of claims 1 to 10, wherein, it further comprises: a target (116), wherein the target (116) is irradiated by the desired electromagnetic wave (114) scattered by the scattering surface (104) of the DCS (102).

12. The radio frequency device (100) according to claim 11, wherein, the target is a receiver (116), and the receiver (116) is configured to receive the desired electromagnetic wave (114) scattered by the scattering surface (104) of the DCS (102).

13. The radio frequency device (100) according to claim 11 or 12, wherein, the DCS controller (112) is further configured to: obtain the characteristics of the desired electromagnetic wave (114) scattered by the scattering surface (104) of the DCS (102) through signaling of the target (116); or obtain the characteristics of the desired electromagnetic wave (114) scattered by the scattering surface (104) of the DCS (102) using information about the target (116).

14. A radio frequency method (200), wherein, it comprises: The transmitter (108) emits (S202) electromagnetic waves (110) onto the scattering surface (104) of the digitally controllable scatterer DCS (102), wherein the scattering surface (104) includes a plurality of scattering elements (106), and each of the scattering elements (106) has a controllable phase shift; The DCS controller (112) determines (S204) a codeword (113) based on one or more parameters of the DCS (102), the characteristics of the electromagnetic waves (110) emitted by the transmitter (108), and the characteristics of the desired electromagnetic waves (114) scattered by the scattering surface (104) of the DCS (102), wherein the codeword (113) determines the phase shift configuration of the plurality of scattering elements (106) of the scattering surface (104) of the DCS (102); The DCS controller (112) uses the codeword (113) to control (S206) the scattering elements (106) of the scattering surface (104) of the DCS (102) to form the desired electromagnetic waves (114) by scattering the electromagnetic waves (110) emitted by the transmitter (108).

15. The radio frequency method (200) according to claim 14, wherein, further comprising: Determine an optimal quadric surface Q based on a quadric surface Q that behaves as a perfect electric conductor PEC, based on the characteristics of the electromagnetic wave (110) emitted by the emitter (108), and based on the characteristics of the desired electromagnetic wave (114) scattered by the scattering surface (104) of the DCS (102). * , where the optimal quadric surface describes the transformation of the electromagnetic wave (110) emitted by the emitter (108) to form the desired electromagnetic wave (114) scattered by the scattering surface (104) of the DCS (102); Determine the phase shift of each of the scattering elements of the scattering surface (104) of the DCS (102) as a function of one or more parameters of the optimal quadric surface Q * .

16. A computer program product comprising program code, wherein, when the program code is implemented on a processor, the program code is used to execute the method according to claim 14 or 15.

17. A radio frequency device (100), wherein, comprising: a digitally controllable scatterer DCS (102), wherein the DCS (102) includes a scattering surface (104), the scattering surface (104) includes a plurality of scattering elements (106), and each of the scattering elements (106) has a controllable phase shift; a DCS controller (112) for: determining a codeword (113) based on one or more parameters of the DCS (102), the characteristics of the electromagnetic waves (110) impinging on the scattering surface (104) of the DCS (102), and the characteristics of the desired electromagnetic waves (114) scattered by the scattering surface (104) of the DCS (102), wherein the codeword (113) determines the phase shift configuration of the plurality of scattering elements (106) of the scattering surface (104) of the DCS (102); using the codeword (113) to control the scattering elements (106) of the scattering surface (104) of the DCS (102) to form the desired electromagnetic waves (114) by scattering the electromagnetic waves (110) impinging on the scattering surface (104) of the DCS (102).

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